High-temperature fan



March 15,1949. N. J. G'RovER 2,464,681

HIGH TEMPERATURE FAN Filed Feb. 19, 1946 INVENTM A/orwaq. GroverPatented Mar. 15, 1949 2,464,681 HIGH-TEMPERATURE FAN Norman J. Grover,Westwood,` Mass., assignor, by mesne assignments, to WestinghouseElectric Corporation, a corporation of Pennsylvania Application February19, 1946, Serial No. 648,756

2 Claims.

This invention relates to the cooling of the hubs of fans used formoving high temperature gases.

Fans are used for moving gases having temperatures as high as 1600 F.The temperature of the gas in one installation may cy-cle between 800 F.and 1600 F. The blades of the fans are under mechanical stress as Wellas being exposed to the high temperatures, and unless the hubs to whichthey are secured, are adequately cooled, the metal in the blades becomesbrittle, and the blades and their joints to the hubs, crack and fail.

When the hubs of such fans are inadequately cooled, the hubs expand awayfrom the shafts and take permanent sets leaving air gaps between thehubs and shafts. The characteristic of metal which resists su-ch apermanent set is called creep strengt The creep strength of steeldecreases very rapidly when heated to temperatures above 900 F.

Attempts have been made to cool the hubs of fans used for hightemperature duties, by .circulating water through the hollow shafts uponwhich the hubs were supported, but such cooling was not effective sothat when the fans were first used with high temperature gases, the hubsexpanded away from the shafts taking permanent sets leaving air gapsbetween the hubs and shafts, which air gaps lessened the heat transferfrom the hubs to the shafts with the result that as the fans continuedto be used with the high temperature gases, the conditions becameprogressively worse. The lives of such fans were relatively short forthe blades soon failed.

This invention provides for circulating cooling water through the hub ofa fan whereby the hub is cooled directly by the water instead of beingcooled through the intermediary of a shaft as has been the practice inthe past. Utilizing this invention, the hub of a fan handling gases thetemperature of which cycled between 800 F. and 1600 F., was cooled to atemperature which varied between 600 F. and 700 F.

An object of the invention is to prevent the overheating of the hubs offans handling high temperature gases.

Another object of the invention is to cool the hub of a fan handlinghigh temperature gases, by circulating a cooling liquid directly inconta-ct with the inner surface of the hub.

The invention will now be described with reference to the drawing, ofwhich:

Fig. 1 is a side elevation, in section, of a centrifugal fan embodyingthis invention, and

Fig. 2 is a sectional view along the lines 2-2 of Fig. 1.

The fan illustrated is of the general type disclosed in detail in the U.S. Patent No. Re. 20,409, and has the casing 6 to which is supported thebearing 'l through which the shaft 8 extends. The inner end of the shafthas the iiange 9 formed thereon and which is attached by the bolts I0 toa similar flange I I on the outer end of the hub I2. The fan blades I3have their root edges joined to the hub as by welding, or they may becast integral therewith.

The shaft 8 has a central longitudinal opening I4, and the hub l2 has asimilar opening I5 aligned therewith. The water supply tube IB extendsthrough the shaft opening I4 and into the hub opening I5 and terminatestherein adjacent the inner end of the tub. The openings I4 and I5 havethe same diameter, and the tube I6 has a substantially smaller outerdiameter whereby water discharged from the tube can circulate around itsexterior surface in the openings I4 and I5.

The tube I6 extends through the packing box I9 into the shaft. The watersupplied through the tube I6, after circulating through the hub and theshaft, is discharged through the pipe 20.

In operation, the water supplied through the tube I6, passes out itsinner end into the opening I5 in the hub I2 and contacts the inner surface of the hub around the opening I5. After traversing the innersurface of the hub it passes out the shaft opening I4 and the pipe 20 towaste or for recooling.

The cooling water is seen to contact the inner surface of the hubthereby directly cooling same.

The bearing 'l as located would be water cooled but since forming nopart of this invention, its cooling details have not been illustrated.

While one embodiment of the invention has been described for the purposeof illustration, it should be understood that the invention is notlimited to the exact apparatus and arrangement of apparatus illustrated,since modifications thereof may be suggested by those skilled in the artwithout departure from the essence of the invention.

What is claimed is:

1. A fan comprising a shaft having a central, longitudinal openingtherein, a hub having a central, longitudinal opening therein, means forattaching one end of said hub to one end of said shaft whereby saidopenings extend in axial alignment, said openings having substantiallythe same diameter, and a liquid supply tube extending through saidopening in said shaft and into said opening in said hub, said tubehaving a sub- 3 stantially smaller diameter than that of said openingswhereby liquid supplied through said -tube into said hub is returnedaround said tube in contact with the inner surface of said hub, saidshaft having means for exhausting the liquid returned around said-tube.

2. A fan comprising a shaft having a central, longitudinal openingtherein and having a ange formed on one end thereof, a hub having aeentral, longitudinal opening therein and having a ange formed on oneend thereof, means for attaching said flanges together whereby saidopenings extend in axial alignment, said openings having substantiallythe same diameter, and a liquid supply tube extending through saidopening in said shaft and into said opening in said hub, said tubehaving a substantially smaller diameter of said openings whereby liquidsupplied through said tube into said hub is returned around said tube incontact with the inner surface of said hub, said shaft having means forexhausting the liquid returned around said tube.

NORMAN J. GROVER.

REFERENCES CITED The following references` are of record in the file ofthis patent:

UNITED STATES PATENTS

